Boron:
Discovered in 1808 by Sir Humphrey Davy, Joseph Louis Gay-Lussac and Louis Jacques Thenard
davy.jpgGay-Lussac.gifthenard.jpg




v Symbol: B
v Atomic number: 5
v Atomic mass: 10.811
v Protons :5
v Electrons:5
v Neutrons:6


v Found: usually found in boron mines in different countries ( Turkey, USA, Argentina, Chile, Russia, China, and Peru


boron_mine.jpg






Form: solid (nonmagnetic)
solid_boron.jpg melting_point.jpg
















Melting point: 2300.0 degrees C (4172.0 degrees F)


Boiling point: 2550.0 degrees C ( 4622.0 degrees F)
boiling_point.jpg



Density:2.34 g/cm3

 Abundance in the earth’s crust: 10 ppm ( parts per million)


Uses: used in agriculture as it plays a notable role in plant fertilisation and in building of cell wall structures, It gives distinctive green flame, hence used in pyrotechnic flares, advanced aerospace structures as a component of composite materials, reducing aldehydes and ketones to alcohols, and in P-type semiconductors as dopant.






Crystal structure: Rhombohedra
rhomboherdra.jpg

Oxidation state: +3


Atomic radius: 85 pm

structure.jpg


Covalent radius: 82 pm
 covalent_radius.jpg


Heat of fusion: 50.2 kJ mol-1

heat_fusion.jpg

Heat of vaporization: 480 kJ mol-1
 vaporization.jpg



Sources: http://www.chemicool.com/elements/boron.html